1. Field of the Invention
The present invention relates to an apparatus and method for determining a HeartBeat Interval (HBI) of an activesync service in a wireless communication system. More particularly, the present invention relates to an apparatus and a method for allowing a client to determine an HBI for transmission/reception of a ping message in a wireless communication system that uses an Exchange ActiveSync protocol.
2. Description of the Related Art
An Exchange ActiveSync protocol is a Microsoft Exchange synchronization protocol optimized for operating in a network having a long standby time and a narrow bandwidth, and is based on a HyperText Transfer Protocol (HTTP) and an eXtensible Markup Language (XML). The Exchange ActiveSync protocol is used for allowing a mobile terminal (referred to as an ‘activesync client’ hereinafter) having a browser function or a Microsoft Windows Mobile function to access information via an exchange server that executes a Microsoft Exchange.
In the conventional exchange activesync based-network illustrated in FIG. 1, an activesync client 100 and an exchange server 110 transmit/receive an ActiveSync Command/Notify message 120 to/from each other. Examples of the ActiveSync Command/Notify message include ping request/ping response messages. The ping request message monitors an account of a relevant client during a specific HBI, and when an event such as an arrival of a new mail occurs, requests the exchange server to notify the occurrence of the event. The ping response message notifies whether an event occurs in the account of a relevant client.
FIG. 2 illustrates a transmission/reception procedure of a ping message in the conventional exchange activesync based-network.
Referring to FIG. 2, when an activesync client 200 transmits a ping request message including an HBI to an exchange server 202 in step 210, the exchange server 202 monitors an account of the activesync client 200 during the HBI, determines whether an event occurs, and when an event does not occur during the HBI as a result of the monitoring, transmits a ping response message informing that an event did not occur during the HBI to the activesync client 200 in step 212.
Then, the activesync client 200, in response to the ping response message, retransmits a ping request message including the HBI to the exchange server 202 in step 214. The exchange server 202 monitors the account of the activesync client 200 during the HBI. When an event occurs as a result of the monitoring, the exchange server 202 transmits a ping response message informing that the event has occurred to the activesync client 200 at the point of occurrence of the event in step 216.
As described above, the ping request and response messages may be transmitted/received frequently or sporadically depending on the HBI and whether an event occurs at a relevant account.
Meanwhile, as illustrated in FIG. 2, the activesync client 200 consumes a predetermined current whenever transmission/reception of a ping request message and a ping response message occurs. If the HBI is seta normal length, the frequency of transmission/reception of the ping request message and the ping response message reduces, so that an amount of a current consumed at the activesync client 200 may be reduced. Since the HBI is set a reasonable length, any error in the network can be detected early enough.
However, when the HBI is set too long, the current consumption increases and an error occurring due to various reasons in an actual network environment cannot be detected. That is, when the activesync client sets a maximum HBI and transmits a ping request message, the activesync client cannot detect a network error until the HBI expires, including the error that occur in the network during the HBI.
Therefore, a technique for reducing current consumption of the client and determining an HBI suitable for a network error state needs to be provided.